Comparison of TSH and Free T4 Hormone Levels in Individuals with Glucose-6-Phosphate Dehydrogenase Deficiency and Healthy Individuals

Background & aim: Iodinated thyroid hormones regulate a variety of biochemical reactions in almost all tissues of the body. These hormones are important factors in the regulation of gene expression in tissues such as; Brain, liver, muscle and adipose tissue are known. Numerous studies have shown that thyroid hormones regulate the activity of the G6PD enzyme. Therefore, the aim of the present study was to determine and compare the levels of TSH and free T4 hormones in individuals with glucose-6-phosphate dehydrogenase deficiency and healthy individuals. Methods: The present descriptive-cross-sectional study was conducted from July 2019 to August 2020. One-hundred and twenty people were included in the study; including 60 individuals with glucose-6-phosphate dehydrogenase deficiency (G6PDD) and 60 individuals with normal glucose-6-phosphate dehydrogenase activity. Blood samples were taken from all individuals and their levels of thyroid enzymes TSH and free T4 were examined. The collected data were analyzed using SPSS software and Kolmogorov-Smirnov, Shapiro-Wilk and Mann-Whitney statistical tests. Results: The mean TSH level in individuals with normal G6PD enzyme activity was 3.46 ± 2.14 and in individuals lacking G6PD enzyme it was 4.09 ± 2.27. This difference in mean TSH between the two groups of patients and healthy individuals was not statistically significant. The difference in mean free T4 levels between individuals with G6PD enzyme activity and individuals with deficiency of this enzyme was very small, as a result that the free T4 level in normal individuals was 11.68 ± 1.61 and in patients was 11.66 ± 1.90, which was not statistically significant. Conclusion: The present study indicated that the TSH hormone level in patients with G6PDD was higher than in individuals with normal G6PD enzyme activity and the free T4 level was slightly lower than in individuals with normal G6PD enzyme activity, although these differences were not statistically significant and overall this study did not show a significant relationship between thyroid hormone levels and G6PD enzyme.